Precision TW electroerosion with superimposed multiple opening guides

Abstract

A traveling-wire (TW) electroerosion apparatus in which at least one of wire guides which are disposed at opposite sides of the cutting zone has a plurality of guide elements with respective circular wire-receptive guide openings each of which is of a diameter substantially larger than a nominal diameter of the electrode wire and which are arranged to be mutually eccentric to make up a composite guide opening such that the diameter of an imaginary cylinder which can be inscribed therein is substantially equal to the nominal wire diameter. Preferably, the guide elements are arranged to be displaceable relative to one another and in their respective planes to change the eccentricity of these guide openings and thus to change the diameter of the imaginary cylinder.

What is claimed is: 
     
       1. An apparatus for electroerosively cutting an electrically conductive workpiece with a continuous electrode wire, comprising: means for axially transporting an electrode wire through a workpiece while defining a cutting zone therewith flushed with a cutting liquid medium;   a pair of wire guide means disposed at opposite sides of the workpiece for providing a straight-line path for the traveling electrode wire therebetween;   power supply means for electrically energizing said cutting zone to erosively remove material from the workpiece; and   cutting feed means for relatively displacing the workpiece and the traveling electrode wire transversely along a programmed cutting path to advance the erosive material removal in the workpiece, wherein at least one of said wire guide means comprises: a plurality of guide elements arranged in the direction of travel of the electrode wire and having respective circular wire-receptive guide openings each of which has a diameter substantially greater than a nominal diameter of the electrode wire, said elements being disposed eccentrically with respect to one another to form a composite opening such that an imaginary cylinder which can be inscribed therein has a diameter which is substantially equal to the nominal diameter of the electrode wire.     
     
     
       2. The apparatus defined in claim 1 wherein said guide elements are supported on support means displaceably substantially parallel to one another, further comprising means for displacing said guide elements to change eccentricity of one circular opening from another, thereby changing said diameter of said imaginary cylinder. 
     
     
       3. An apparatus for electroerosively cutting an electrically conductive workpiece with a continuous electrode wire, comprising: means for axially transporting an electrode wire through a workpiece while defining a cutting zone therewith flushed with a cutting liquid medium;   a pair of wire guide means disposed at opposite sides of the workpiece for providing a straight-line path for the traveling electrode wire therebetween;   power supply means for electrically energizing said cutting zone to erosively remove material from the workpiece;   cutting feed means for relatively displacing the workpiece and traveling electrode wire transversely along a programmed cutting path to advance the erosive material removal in the workpiece, wherein at least one of said wire guide means comprises:   a plurality of guide elements arranged in the direction of travel of the electrode wire and having respective circular wire-receptive guide openings each of which has a diameter substantially greater than a nominal diameter of the electrode wire, said elements being disposed eccentrically with respect to one another to form a composite opening such that an imaginary cylinder which can be inscribed therein has a diameter which is substantially equal to the nominal diameter of the electrode wire; and   means associated with said at least one guide means for rotating at least one of said guide elements which among the others lies the closest to said workpiece, about an axis of rotation substantially coincident with the axis of said imaginary cylinder so as to maintain the axis of the opening of said closest guide element that it lies spaced from said axis of rotation in a direction which is parallel but opposite to the direction of a force acting on said traveling wire in said cutting zone and varying as a function of change in the course of the wire along said programmed cutting path.   
     
     
       4. An apparatus for electroerosively cutting an electrically conductive workpiece with a continuous electrode wire, comprising: means for axially transporting an electrode wire through a workpiece while defining a cutting zone therewith flushed with a cutting liquid medium;   a pair of wire guide means disposed at opposite sides of the workpiece for providing a straight-line path for the traveling electrode wire therebetween;   power supply means for electrically energizing said cutting zone to erosively remove material from the workpiece;   cutting feed means for relatively displacing the workpiece and the traveling electrode wire transversely along a programmed cutting path to advance the erosive material removal in the workpiece, wherein at least one of said wire guide means comprises: a plurality of guide elements arranged in the direction of travel of the electrode wire and having respective circular wire-receptive guide openings each of which has a diameter substantially greater than a nominal diameter of the electrode wire, said elements being disposed eccentrically with respect to one another to form a composite opening such that an imaginary cylinder which can be inscribed therein has a diameter which is substantially equal to the nominal diameter of the electrode wire, said guide elements being supported on support means displaceably substantially parallel to one another and means for displacing said guide elements to change eccentricity of one circular opening from another, thereby changing said diameter of said imaginary cylinder; and     means associated with said at least one guide means for rotating at least one of said guide elements which among the others lies the closest to said workpiece, about an axis of rotation substantially coincident with the axis of said imaginary cylinder so as to maintain the axis of the opening of said closest guide element that it lies spaced from said axis of rotation in a direction which is parallel but opposite to the direction of a force acting on said traveling wire in said cutting zone and varying as a function of change in the course of the wire along said programmed cutting path.